"It's in line with international practice to collect female virgins' blood samples, which serve as negative control substances in HPV research, given that the risk of contracting HPV is low among women who have never had sex," hospital spokeswoman Guan Jiuping told China Daily.

Researchers would take the donors' word for their sexual status, Jiuping said.

Many users of Weibo, China's Twitter equivalent, slammed the researchers' virgin blood study, saying it was demeaning to women.

"Male virgins are not needed, just females, how is this science?" wrote one user wrote.

Others voiced their concern that the study would perpetuate the outdated notion that all Chinese women must be virgins until marriage.

"The continued importance attributed to virginity, combined with relaxed sexual mores in recent decades, has led to growth in the market for artificial hymens and restorative surgery which allows women to appear to be virgins," AFP noted.

But health experts insist the study is only for purely medical research and is not meant to imply that Chinese women should be virgins.

"Too much attention to sensitive words like 'virgin' and 'sex' is not necessary in this context," Jiuping said.